Method of melting and treating metals.



No. 708,783. Patented Sept. 9, |902.

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METHOD F- MELTING AND TREATING METALS.

(Applicatin led June 13l 1901,)

UNITED STATES PATENT OFFICE.

EDWARD H. SCHWARTZ, OF CHICAGO, ILLINOIS, ASSIGNOR TO THEHAWLEY DOWN DRAFT.FURNACE COMPANY, OF CHICAGO, ILLINOIS, Av CORPORA- TIoN on ILLINOIS.

METHOD OF NMELTING AND TREATING- METALS. I.

SPECIFICATION forming part of Letters Patent No.1708,783, dated September 9, 1902. Application tied Jun@ 13, 1901. serial No. 64.370. (No specimens.)

To @ZZ whom, it may concern:

Beit known that I, EDWARD H. SCHWARTZ, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Method of Melting and Treating Metals, of which the following is a specification. v

My invention relates to what may be termed a melting-furnace, and it consists of the 1o novel and useful method or process of melting and treating metals, more particularly brass, malleable iron, and steel, said method being characterized by the application of a blast or 4blasts of hydrocarbon or oxyhydrocarbon iiame directly upon the metal until' melted, after which by the tilting of the melting-furnace the blast may be caused to penetrate and agitate the molten metal, and thereby bring about the necessary reactions zo for purifying or freeing the metal from metalloids.

For the purpose of affording a clear and definite understanding of-my invention, but without any intention oflimitation thereof,

I have chosen to show a form ofrmelting-furnace in which my method may be conveniently practiced, although'such method may be practiced by other forms of apparatus and constructed on the same general principles.

3o In the accompanying drawings, Figure I is a sectional elevation of the selected meltingfurnace taken on line l 1 of Fig.' 2 andenlarged as compared with the other'igures of the drawings. Fig. 2 is a plan view of the furnace. Fig. 3 is a sectional elevation on the line 3 3 of Fig. 2, and FigMI is a diagrammatic view showing the general course and action of the blasts or jets from the burners.

The construction of the melting-furnace and the method herein claimed will be described more or less together. This furnace comprises a shell' l, substantially hemispherical at the bottom and truncated conical at its top, which has a charging-opening adapted to be closed by a door 2. Communicating with the lower portion of the furnace is a lateral spout or opening 3, which extends obliquely upward and serves both as a vent for the escape of gases, te., and also as a 5o discharge or tap for drawing off the molten metal. The bottom of the furnace is made as a removable section 4.,.held to the other part of the casing or furnace by means of bolts 5 or in any other suitable and desired 55 manner. The interior of the furnace is suitably lined with refractory material. The furnace is adapted to oscillate in a frame composed of the two upright standards 6, having at their upper ends suitable bearings 6o adapted to receive the hollow trunnions on the opposite side of the furnace. In the present instance two air-supply pipes 8 enter the hollow trunnions, while the oil or gas is introduced into the air-supply through the two pipes 9, governed by valves 10, the same constituting hydrocarbon or oXyhydrocarbon burners. Pipes or passages l1 communicate with the trunnions and constitute mixingchambers and are adapted to convey the 7o vapor to the two burners 12. These burners are so directed downwardly and convergingly toward the wall opposite to that in which they are located as to focus their jets at the point 13 (see Fig. 4.) substantially at 75 the central vertical axis of the furnace, after which the jets lseparate outward and away from each other, and are nally deiiected laterally and 'downwardly with a whirling movement'and then forwardly, so that the 8o Vflame at thetime of its complete combustionfand greatest heat will be in direct and jintimate contact with the metal supplied to the furnace. A general idea of the direction and action of the jets of flame will be understood from the diagrammatic View, Fig. 4.

- By simply manipulating suitable valves governing the air-supply and the gas or oil supply it is possible to obtain an oxidizing-flame, either a reducing or neutral iiame. For in- 9o stance, by increasing the proportionof oil or gas the flame may be changed from an oxidizing-iiame to a reducing-flame. Suitable mechanism is used for tilting or oscillating the `furnace, the mechanism here shown consis-ting of a rack I4, secured to the bottom of the furnace and adapted to be engaged by a pinion 15, mounted on the cross-shaft16, bearing at its ends in the standards 6. Thefurnace having been charged with metal through the top or charging door, the vapor-jets are started and ignited in any suitable way. The vapor is raised to an extremely-high temperature and complete combustion occurs toward the bottom of the furnace in contact with the metal itself, which rapidly becomes melted by this direct and forcible application of flame thereupon. In the above operation either the neutral or the reducing flame or the oxidizing-flame may be used, depending upon the character of the metal to be melted, and in the same melting operation the flame may be changed from one to the other of said kind of flames, as may be determined by the operator. In the melting of brass it may be desirable to rst start with a flame having a suitable excess of carbon, after which the excess of carbon may be increased, and finally the flame may be changed to be substantially the same in character as the flame first applied. The llame which is applied to the metal as above stated is a whirling or rotating flame, which sweeps across the metal. In the present instance and by preference this flame is a llame composed of a plurality of flame-jets emanating from the upper portion of the furnace above the plane of the vent-opening. These flame-jets, being downwardly directed and converging, combine to form a single llame, which by striking the opposite curved wall of the furnace is given a rotating movement across and in contact with the metal before finding exit through the vent-opening. This llame is therefore caused to move rearwardly above the metal and thence downwardly and forwardly over and in Contact with the metal, and in practice such flame makes a complete circle by sweeping across the metal a second time before passing out through the vent-opening, which is arranged below the point of entrance of fuel into the furnace. If it is desired to purify or free the molten metal (more particularly iron and steel) of metalloids, the bottom of the furnace is tilted or oscillated forward-that is, to the left (see Fig. 1)--to such a position that the molten metal will be in the direct path of the blast or jets, but in front or rather below the focusing-point of these blasts or jets, whereby the latter will penetrate the molten metal and keep it in a state of violent agitation. At the same time the hydrocarbons will cause the necessary reactions for bringing about the purification of the metal. By tilting or oscillating the furnace in the opposite direction the metal can be poured off through the vent opening or spout. It is understood that the pipes 8 have a swiveling connection with the hollow trunnions, so as to permit the oscillation above described. My novel process therefore consists broadly in the application to the metal of a flame whirling or rotating in a substantially vertical plane and arranged to sweep across and in contact with thc metal,

and a second feature contemplates the penetration of molten metal by the llame itself. When the furnace is in its upright position, as shown in the drawings, at which time the actual melting takes place, either a reducingflame or a neutral llame may be employed, as determined bythe operator. Vthemhowever, the furnace is tilted, as hereinbefore referred to, the mass of molten metal will be brought into the path or line of direction of the jets, which will thereupon strike against and penetrate such mass, and the flame of the jets will be such as desired by the operator, according to the particular character of the metal being treated and the particular character of product sought. In this novel stage of the treatment of some metals, such as brass, it will be understood that either a reducing-flame or a neutral llame may be used, while in the case of steel and malleable iron, for instance, an oxidizing-flame may be used. Particularly in the Vcase of brass and the like this penetration of the molten mass by the llame itself is of importance and utility, inasmuch as it gives that violent agitation or boiling and the consequent results which occur when, as in ordinary practice, the molten brass is pole( as it is called-that is, stirred by a long wooden pole, usually of green birchwood. In case the brass, copper, or bronze becomes of the same condition as results from overpoling under the old process,and thereby becomes brittle, it may be brought back to proper condition by passing free air through the furnace or by using my oxidizing-flame.

I claiml. The method of melting metals which consists in combining a plurality of llame-jets into a single llame, giving this flame a whirling movement and bringing it into contact with the metal to be melted; substantially as described.

2. The method of melting metals which consists in introducing into a melting-chamber from one side only thereof and ata point above the metal a plurality of downwardlydirected flame-jets which meet and combine into a single flame, and causing the flame to rotate in a vertical plane and in contact with the metal; substantially as described.

3. The method of melting metals which consists in combining a plurality of flames into a single flame and causing this llame to move downwardly and thence forwardly over and in contact with the metal; substantially as described.

et. The method of melting metals which consists in causing a flame to move rearwardly above the metal, -thence downwardly and forwardly over and in contact with the metal and then to sweep a second time rearwardly, downwardly and forwardly over and in contact with the metal and thence out from the furnace; substantially as described.

5. 'Ihe method of melting metals which consists in causing ailame to move laterally over and in contact with tho surface of the metal,

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thereby melting it, and then changingthe direction of movement of the flame relative to the metal and causing it to impinge directly upon and penetrate into the body of molten metal; substantially as described.

6. The method of melting metals which consists incausing a liame to move laterally over and in contact with the surface of the metal, thereby melting it, and then bringing the molten metal directly into the path of the ame and causing the flame to impinge directly upon and penetrate into the body of molten metal; substantially as described.

7. The method of melting metals which consists in causing a flame to rotate downwardly upon and thence forwardly over andin contact with the surface of the metal, thereby melting it, and then changing the direction of movement of the fiame relative to the metal and causing it to impinge directly upon and penetrate into the body of molten metal; substantially as described. v

8. The method of melting metals which consists in causing a hydrocarbon-llame to rotate downwardly uponand thence forwardly over and in contact with the surface of the metal, thereby melting it, and then changing the direction of movement of the llame relative to the metal and causing it to impinge directly upon and penetrate into the body of molten metal; substantially as described. n

9. The method of melting` metals which consists in combining a pl'urality of flames into a single flame, causing such flame to move laterally over and in contact with the surface of the metal, thereby melting it, and then causing such flame to impinge directly upon and penetrate into the body of molten metal; substantially as described.

10. The method of melting metals Iwhich consists in causing a llame to enter a furnacechamber containing the metal and move rearwardly above the metal andn thence downwardly and forwardly over and in .contact with the metal, and removing the products of combustion from the furnace at such a point that they do not come in contact with the enteringiiame at a point below that of entrance of fuel into the furnace; substantially as described.

11. The method of melting metals which consists in combining a plurality of ames into a single flame and causing this llameV to Inovedownwardly and thence forwardly over and in contact with the metal, and removing*- the products of combustion from the furnace at a point below that of entrance of fuel into the furnace; substantially as described.

12. The method of melting brass which consists inl applying to the i brass, to be melted a llame which at its first application contains a certain excess of carbon and subsequentlyl SCHWARTZ. 

